Characteristics of the Series Resistance Extracted From Si Nanowire FETs Using the Y-Function Technique

The series resistance, R-sd in silicon nanowire FETs (Si-NWFET) is extracted unambiguously, using the Y-function technique, in conjunction with the drain current and transconductance data. The volume channel inversion in Si-NWFET renders the charge carriers relatively free of the surface scattering and concomitant degradation of mobility. As a result, the Y-function of Si-NWFET is shown to exhibit a linear behavior in strong inversion, thereby enabling accurate extraction of R-sd. The technique is applied to nanowire devices with channel lengths 82, 86, 96, 106, 132, and 164 nm, respectively. The extracted R-sd values are shown nearly flat with respect to the gate voltage, as expected from Ohmic contacts but showed a large variation for all channel lengths examined. This indicates the process parameters involved in the formation of series contacts vary considerably from device to device. The present method only requires a single device for extraction of R-sd and the iteration procedure for data fitting is fast and stable.